Kinetics of Solidification of Supercooled Liquid Mercury Droplets

TLDR

The solidification rate of supercooled liquid mercury droplets is strongly dependent on foreign substances on their surface or suspended within them. The authors consider several hypotheses to explain the observed multiplicity of solidification frequencies. Mercury laurate–coated droplets solidify at rates proportional to volume, consistent with homogeneous nucleation, while mercury acetate–coated droplets solidify at rates proportional to area, consistent with heterogeneous nucleation; Hg₂I₂-coated droplets suggest nucleation by suspended crystallites, and some dispersions exhibit multiple solidification frequencies per area or volume.

Abstract

The solidification rate of supercooled liquid mercury droplets is strongly dependent upon the nature of foreign substances on their surface or suspended in them. Droplets (2–8 microns diameter) coated with mercury laurate solidify at rates that are proportional to droplet volume and satisfactorily described by the theory of homogeneous nucleation of crystals. Droplets coated with mercury acetate solidify with frequencies that are proportional to droplet area and in good agreement with the theory of heterogeneous nucleation. The results on Hg2I2-coated droplets are interpreted on the hypothesis that nucleation is effected by suspended crystallites of one kind. For some droplet dispersions the kinetic results are apparently best described by a multiplicity of solidification frequencies/area or volume. Various hypotheses for this multiplicity are considered.